NEW YORK (AP) — Scientists have created the first comprehensive view of how human DNA works. And they say it will rewrite the textbooks and give valuable new insights into the biology of what goes wrong in disease.

The new work reveals complicated systems for controlling where and when our genes are active.

The research also shows that at least 80 percent of our DNA is actively participating in biological processes. That’s far more than just the 2 percent occupied by our genes. Researchers said the extent of that activity was a surprise.